@Kestrelon they are. Pets during Lift-Off or Proto-Strike can be reached by opponent performing the same. Of course a pet suspended in the skies won't reach the one hidden underground and the other way around. (Forgive a cheap rhyme!)

Even if you don't battle a lot, for the unique numbers themselves you'd keep an H/P one. Leave the H/H stats to Scooter the Snail.

Very interesting occurence I thought I'd share, discovered while I was looking to tame one of these; if two opposing pets have an underground avoid and use it at the same time (ie, the Water Snake's "Burrow"...and the Shimmershell's "Dive"), the combat round will continue as if nothing happened!

My snake burrowed, the snail dove, and the snake moved in for a normal attack! Could come in handy...and it makes me wonder if the airborne versions are the same!

•Alongside Scooter, this snail has the best of both snail worlds that really matter. Even when it comes to P, a snail will not be a big hitter. It's all about their H, and at 1969, its among the top 10 of most healthful pets. Coupled with Shell Shield and Dive, its longevity during battled is significantly increased.

After a few battles, I found a rare as a secondary to another shimmershell snail. It was a level 6, so looks like that is the lucky number. I found it along the shore next to Remtravel's Excavation site. =D

I found mine at the uppermost northern part of Mists Edge on the shore. The first one a level 3 rare. I was so happy never had that happen to me. I normally have to spend a good part of the day doing pet battles to find a rare. I saw several along the coast dont know if it was the time of day. It was on a Sunday 4:50 Central Time.

Thank you to Devlan on the advice to battle the Darkshore Cubs for the chance to get a rare as a secondary. I had flown the entire shore and only seen a few snails and neither of them were any good. After only challenging 3 bears, one of them brought his rare snail friend along!